You can also embed plots, for example:
## Warning in colors(.): Some values were outside the color scale and will be
## treated as NA
## Warning in colors(.): Some values were outside the color scale and will be
## treated as NA
## Warning in colors(.): Some values were outside the color scale and will be
## treated as NA
## Warning in colors(.): Some values were outside the color scale and will be
## treated as NA
Note that the echo = FALSE parameter was added to the
code chunk to prevent printing of the R code that generated the
plot.